Data terminals for communication with computers are well known. For example, U.S. Pat. No. 4,115,870 to Lowell teaches a small light weight hand-held battery powered data terminal with which a salesman enters orders for products including information such as the product code, quantity, nature of payment and the like. A customer identification number is entered and order information that has been entered may be recalled. Data entered is transmitted to a central terminal by way of a telephone connection. A display is employed to visually indicate the information being ordered.
Other data terminals of various types are shown and described in U.S. Pat. Nos. 4,277,837 to Stuckert; 3,976,840 to Cleveland, 4,090,247 to Martin, 4,032,931 to Haker and 3,792,444 to Spinner.